There are many circumstances in which it is desirable to dispense labels one at a time, especially where an operator applies individual labels to objects. That is, there are many circumstances when manual or semiautomatic dispensing of labels is desirable, and apparatus for effecting that dispensing is well known in the art for dispensing labels mounted on liners (such as exemplified by U.S. Pat. No. 3,653,539).
Recently, there have been substantial developments in the production of linerless labels, which have a number of advantages with respect to labels mounted on liners. While equipment exists for automatically dispensing linerless labels, such as shown in U.S. Pat. Nos. 4,468,274 and 4,978,415, and copending application Ser. No. 07/907,511 filed Jul. 1, 1992, such equipment is relatively complex, and is suited primarily for continuous operation. There is a need for a method and apparatus for dispensing linerless labels periodically or intermittently, so that one label is dispensed at a time, the apparatus operating semiautomatically.
According to the present invention, a method and apparatus are provided for dispensing linerless labels in a continuous web. In the continuous web each label is typically separated from adjacent labels in the web by a line of weakness (perforation), and the web is in roll form. Each label has an adhesive face and a non-adhesive face, the adhesive face typically being on the inside of the roll. The labels are dispensed according to the present invention utilizing simple apparatus in a manner such that one label at a time is exposed and available to be detached from the roll.
According to one aspect of the present invention a method for dispensing linerless labels is provided which comprises the following steps: (a) Mounting the roll for rotation about an axis of rotation. (b) Periodically or intermittently positively pulling the web from the roll an amount sufficient to unwind approximately one length of label from the roll. (c) Exposing a free edge of the leading label in the roll so that it may be grasped. (d) Grasping and pulling on the free edge of the leading label in such a manner so as to separate the leading label from the roll. And (e) after the leading label is separated from the roll, automatically initiating steps (b) and (c) to expose the free edge of the next label in the roll.
Step (b) is typically practiced by engaging the adhesive face of the linerless label with the circumferential periphery of the drive roller so that the web wraps around at least about 170 degree of the circumferential periphery thereof (e.g., about 180-200 degrees), and is further practiced by engaging the adhesive face as and after it engages the circumferential periphery of the drive roller with a plurality of conveyor tapes spaced from each other in a direction parallel to the axis of the rotation of the roll and also after the label passes the circumferential periphery of the drive roller. Step (c) is practiced by separating the leading edge of the web from the conveyor tapes after the web is past the drive roller.
The method is typically practiced utilizing a stationary cutting blade adjacent the web, and step (d) is practiced by manually moving a line of weakness of the web into contact with the cutting blade so as to sever the leading label from a preceding label of the web. Step (e) is typically practiced by automatically sensing the position of the web with respect to the cutting blade utilizing a pair of optical sensors which sense marks on the web which are spaced from each other the length of a label.
The roll is typically automatically braked after step (b) is terminated, and at start-up the position of the web is jogged until the line of weakness of the leading label is aligned with the cutting blade, and the optical sensors are positioned to properly sense unwinding of one length of label at a time.
According to another aspect of the present invention a linerless label dispenser is provided. The dispenser comprises: Means for mounting the roll of linerless labels so that the labels may be pulled from the roll in web form as the roll rotates about a first axis of rotation. Drive means for unwinding the web of linerless labels from the roll, the drive means comprising a drive roller having a circumferential periphery and rotatable about a second axis, parallel to the first axis. An exit roller, rotatable about a third axis, parallel to the second axis. A plurality of endless conveyor tapes extending over a portion of the circumferential periphery of the drive roller and engaging the exit roller, to effect transport of the label web past the drive roller and to and past the exit roller, the conveyor tapes spaced from each other in a direction parallel to the second axis. Separation means for separating the linerless label web from the conveyor tapes. And severing means for severing each label from the next label of the web of linerless labels.
In the dispenser, typically an idler roller is also mounted between the roll mounting means and the drive roller for engaging the non-adhesive face of the web of linerless labels between the roll mounting means and the drive roller circumferential periphery, and tensioning the web. The drive means typically comprises a motor for rotating the drive roller, and there is also provided automatic sensing means for sensing the position of the web from the roll and controlling the motor in response to the sensing. The automatic sensing means typically comprises first and second optical sensors, a first sensor mounted adjacent the drive roller, and a second sensor mounted past the drive roller adjacent the separation means. Typically, control means are provided for controlling operation of the motor in addition to the automatic sensing means, to turn it off, turn it on so that it operates automatically under the influence of the sensors, or to "jog".
The conveyor tapes are wrapped around the exit roller to protrude a first radial distance from the circumferential portion of the exit roller. The separation means comprises rings on the exit roller between the conveyor tapes, the rings protruding a second radial distance from the circumferential portion of the exit roller, the second radial distance being greater than the first radial distance so that the rings peel the label away from the conveyor tapes.
The severing means may comprise a stationary knife blade mounted adjacent the drive roller. The roll mounting means typically includes brake means to prevent the roll from continuing to unwind when driving action by the drive means is interrupted. The drive roller, conveyor tapes, exit roller, roll mounting means and idler roller are typically mounted with respect to each other so that the web from the roll engages at least about 170 degrees of the circumferential periphery of the drive roller, which--combined with the adhesive face of the web engaging the drive roller and conveyor tapes--provides positive unwinding action. The roll mounting means may comprise a substantially vertical shaft, which has a pair of adjustable chucks mounted on it to accommodate various widths of rolls.
It is the primary object of the present invention to provide a simple method and apparatus for semiautomatically dispensing linerless labels. This and other objects of the invention will become clear from an inspection of the detailed description of the invention, and from the appended claims.